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| author | Mark Rutland <mark.rutland@arm.com> | 2016-11-03 23:23:12 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-11-11 21:25:45 +0300 |
| commit | 1b7e2296a822dfd2349960addc42a139360ce769 (patch) | |
| tree | caf118cceca10b7a7ecc3ab7b3019f52d1d409ed /arch/arm64/include/asm/assembler.h | |
| parent | 57c82954e77fa12c1023e87210d2ede77aaa0058 (diff) | |
| download | linux-1b7e2296a822dfd2349960addc42a139360ce769.tar.xz | |
arm64: assembler: introduce ldr_this_cpu
Shortly we will want to load a percpu variable in the return from
userspace path. We can save an instruction by folding the addition of
the percpu offset into the load instruction, and this patch adds a new
helper to do so.
At the same time, we clean up this_cpu_ptr for consistency. As with
{adr,ldr,str}_l, we change the template to take the destination register
first, and name this dst. Secondly, we rename the macro to adr_this_cpu,
following the scheme of adr_l, and matching the newly added
ldr_this_cpu.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Laura Abbott <labbott@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/include/asm/assembler.h')
| -rw-r--r-- | arch/arm64/include/asm/assembler.h | 19 |
1 files changed, 15 insertions, 4 deletions
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h index 28bfe6132eb6..128a9ca06c8a 100644 --- a/arch/arm64/include/asm/assembler.h +++ b/arch/arm64/include/asm/assembler.h @@ -202,14 +202,25 @@ lr .req x30 // link register .endm /* + * @dst: Result of per_cpu(sym, smp_processor_id()) * @sym: The name of the per-cpu variable - * @reg: Result of per_cpu(sym, smp_processor_id()) * @tmp: scratch register */ - .macro this_cpu_ptr, sym, reg, tmp - adr_l \reg, \sym + .macro adr_this_cpu, dst, sym, tmp + adr_l \dst, \sym mrs \tmp, tpidr_el1 - add \reg, \reg, \tmp + add \dst, \dst, \tmp + .endm + + /* + * @dst: Result of READ_ONCE(per_cpu(sym, smp_processor_id())) + * @sym: The name of the per-cpu variable + * @tmp: scratch register + */ + .macro ldr_this_cpu dst, sym, tmp + adr_l \dst, \sym + mrs \tmp, tpidr_el1 + ldr \dst, [\dst, \tmp] .endm /* |